1. Field of the Invention
The present invention relates to an electronic calculator with a graph displaying function. More particularly, the present invention relates to an electronic calculator with a graph displaying function capable of storing a plurality of screen images having a graph or the like drawn thereon.
2. Description of the Related Arts
Conventional electronic calculators with a graph displaying function can merely store data such as a numeral, a character string, and a formula in a storage device by individually attaching an index thereto.
Therefore, when one of these data stored in the storage device is to be deleted or rearranged, it is necessary to select an object from these data and edit the object only on the basis of the index attached to the object, raising a problem that the object is liable to be mistakenly edited.
Moreover, in such a conventional electronic calculator, it is not possible to store a drawn screen image as it is. Therefore, when a calculation of a formula or a display of a graph involving a complex and time-consuming calculation is to be repeated for a number of times, it is necessary to perform calculation again by using the stored formula before drawing and displaying the graph. In other words, every time the data are displayed, the indices of the data must be designated and recalled, and the same procedure must be repeated for a number of times, which is a cumbersome operation.
In the meantime, as an electronic calculator applicable to an OHP (Over Head Projector) in a conference or a meeting, Japanese Unexamined Patent Publication No. HEI 09(1997)-297656 proposes an electronic apparatus comprising a receiving device and a transmission-type display device for OHP, in which a mark indicating an arbitrary position of the data or graph displayed on a display device can be pointed at and operated on the data input device side capable of transmitting data without the pointing operation on the main body side.
According to the above electronic apparatus disclosed in Japanese Unexamined Patent Publication No. HEI 09(1997)-297656, the displayed data can be pointed at clearly by moving the mark to an arbitrary position relative to the data or graph. However, the above electronic apparatus is not constructed in such a manner that, by successively reading out and displaying a plurality of displayed data which are stored, the contents of the displayed data are dynamically expressed in some sort so that the contents of the displayed data may be better understood.